Lubricant



wamcan'r No Drawing. Application August ,18, 1936, Serial No. 98,653

res PATENT QFFHC This invention relates to lubricants and moreparticularly to a lubricant suited for use in an internal combustionengine and a method of making same.

6 Recent developments in the art of refining oils for the lubrication ofinternal combustion engines have resulted in the general acceptance oradoption of a method which may be referred to as a selective solventextraction method. Gener- 10 ally the selective solvent extractionmethod referred to includes a treating of that'oil which remains afterthe removal by distillation of the gasoline and other light constituentsof the crude oil. By the use of certain solvents, acids, alkalis,

methods of heating and cooling and/or centrifuging the oil, it ispossible to separate the lubricating oil from the waxes, asphalts andother undesirable matter to produce that which is known in the art as adc-waxed oil characterized by the fact that it will maintain asubstantially constant viscosity throughout wide variations intemperature.

Among the defects found in the "dc-waxed oil produced according to thevarious selective solvent extraction processes is one which relates toits oiliness and its power to penetrate and maintain a tough, thin filmon bearing surfaces. Numerous attempts have been made to cure thisdefect inherent in selective solvent extraction oils. It has beenproposed to restore some of the desirable oiliness characteristics ofthe solvent extraction oil by the use of a fatty acid. Variousphosphorous and chlorinated compounds have been employed in attemptstoimprove the 85 characteristics of the "de-waxed oil". In numerousinstances, however, it has been found that although certain acids orother compounds may be added to restore the oiliness characteristic ofthe lubricant the resultant lubricant is 40 rendered undesirable byreason of certain adverse efiects upon the bearing surfaces of the motorin which the lubricant is employed. For instance solvent extractionmotor oils when treated with certain fatty acids to restore the oiliness45 characteristic have been found to have an extremely corrosive efiectupon bearing material as employed in modern internal combustion engineconstruction. In other instances excessive oxidation or break down andsludging of the oil 50 in the engine has followed where fatty acids,phosphorus and chlorinated compounds were added to the solventextraction motor oil to restore some of the oiliness characteristics.

All oils heretofore produced for use in internal 56 combustion engineswhether by the conventional fractional distillation methods or by theselective solvent extraction methods have lacked certain desirablecharacteristics, among which are the ability of the lubricant to act asa rust inhibitor and to act as an anti-oxident so as to prevent a 5sludgingof the oil when subjected to the heat and agitation ofoperation.

It is among the objects of my invention to provide a lubricant whichwill possess all of the -desired oiliness or lubricating qualitites,which will 10 act as a rust inhibitor and which will not oxidize or forma sludge during operation. It is a further object of my invention toprovide a lubricant for internal combustion engines which willcorrespond with respect to viscosity and temperature 15 characteristicsto lubricants made according to the selective solvent extractionprocesses and which will correspond with respect to the oiliness thereofto lubricants produced according to fractional distillation methods andwhich will not 20 contain any substances such as would cause orfacilitate rapid corrosion of the parts of the engine or cause orfacilitate an oxidation and sludging of the lubricant while in use. Itis a further object of my invention to provide a lubricant 5 which iscomposed of mineral oil and sulphurized sperm oil. It is a furtherobject of my invention to provide a sulphurized oil which is soluble inparaffin base oil such as, for instance, Pennsylvania. oils. It is afurther object of my invention to 30 chemically combine and introducesulphur in an internal combustion engine lubricant in a form wherein thesulphur is deprived of its corrosive effect and yet retains itscatalytic high pressure lubricant effect. Further objects and advantagesrelating to simplicity of procedure and economy of manufacture willappear from the following description.

Sperm oil is a substance obtained from the head and body of the spermwhale and comprises a mixture of triglycerides and waxes. The degree ofunsaturation of both the constituent fatty acids and fatty alcohols, aswell as the ratio of triglycerides to wax varies considerably, dependingupon whether the oil is obtained from the head or from the body of thewhale. Sperm oil as known to commerce and as I have used it in thisspecification is a mixture of both head and body oil and the percentageof wax in the sperm oil will vary from between 60% to 80% withcorresponding variations in glyceride content. The sperm oil wax is anester of a long chain fatty alcohol. The fatty acids which are containedin both triglyceride and wax and the fatty alcohols which are found inthe wax only vary in chain lengths from 10 to 20 carbon atoms, thegreater portion being of 16 and 18 carbon chain lengths. By "wax" asused herein 1 mean a mixture of the esters of long chain fatty alcoholsof varying unsaturation and chain lengths.

As a specific example of a method of preparing a lubricant according tomy invention I place any desired quantity of sperm oil in a suitabletank or vessel and raise the temperature thereof by any suitable meansto about 300 1". The heated sperm oil is agitated and during theagitation thereof sulphuris added which may be in the form of flowers ofsulphur until the sulphur content comprises about 8 to 10% of thecontents of the tank or vessel. While I have observed that the sulphurmay be added up to about 15% without seriously adversely aflecting thefunction of the resultant product which I will refer to as a sulphurizedsperm oil, I prefer to limit the quantity of sulphur to about 10% toinsure that there will be no excess of sulphur in the lubricant in itsfinal form.

It appears that the esters referred to above have the power to take upsulphur and the addition of the sulphur to the unsaturated esters,according to my method, combines the sulphur so that following thecombination the sulphurized sperm oil wax functions to preventcorrosion. Although the exact nature of the chemical reaction takingplace between the wax and the sulphur is not definitely known I havefound that the resultant product possesses certain valuablecharacteristics or properties when used as or blended with a lubricant.The combination of the wax and sulphur seems to prevent oxidation andcorrosion. Although I am aware that sulphurized fatty oils have beenemployed to improve lubricants heretofore and undoubtedly do possesscertain advantageous characteristics, their disadvantages such as theirtendency to oxidize and break down have rendered them unsuited for manyuses. Since sperm oil may contain about 35% of triglyceride thesulphurized sperm oil also contains a considerable quantity of amaterial corresponding to a sulphurized fatty oil such as heretoforeknown in this art. It appears however that the presence of about 65% ofsulphurized wax inhibits or prevents the normal adverse effects arisingfrom the use of sulphurized glycerides.

Following the sulphurizing of the sperm oil the sulphurized sperm oilmay be cooled and added to a suitable mineral oil in quantities ofbetween A of 1% and 1%. More than 1% sulphurized sperm oil may be addedbut I have found a lubricant containing less than 1% to have thecharacteristics desired and since up to 1% of the sulphurized sperm oilis insufficient to effect any appreciable change in the gravity, flash,fire, viscosity and cold tests I prefer to use less than 1%. The mineraloil which thus serves as a base for the lubricant may be mineral oilresulting from the conventional fractional distillation method or ade-waxed mineral oil made according to a selective solvent extractionmethod heretofore referred. to. The mineral oil stock employed may be ofthe parafllnic base type such as Pennsylvania oil or of the asphalticbase type, or of any other type since the sulphurized sperm oil issoluble in all types so as to form a suitable combustion enginelubricant. In the event that the oil employed is of the de-waxed orselective solvent extraction type I have found that the addition ofbetween of 1% and up to 1% of the sulphurized sperm oil restores the oilto a degree of "oiliness" which is equal to or superior to thatresulting from the conventional fractional distillation.

An alternative method of preparing a lubricant according to my inventioncomprises mixing sperm oil and mineral oil and thereafter adding thesulphur. According to this alternative the sperm oil may comprise aboutV. of 1% up to 1% of the sperm oil and mineral oil mixture and theamount of sulphur added may correspond substantially to the amount addedaccording to the preferred methodoutlined above. The sulphur and spermoil combine in the sperm oil and mineral oil mixture to produce asulphurized sperm oil and mineral oil mixture corresponding to thatproduced by the preferred method.

Regardless of the nature of the mineral oil employed in conjunction withthe sperm oil and sulphur the resultant lubricant possesses a number ofimportant desirable characteristics as de from the "oiliness" thereofwhich are not found in other types of lubricant and which result fromthe action of the sulphurized sperm 011. One of said characteristics isthe action of the resultant lubricant as a rust inhibitor and in thisrespect the lubricant produced according to my invention supplies a longfelt need in the internal combustion engine lubricant art.

A second desirable characteristic of a lubricant produced according tomy invention is the function of the same as an anti-oxident. Thesulphurized sperm oil as described above appears to deprive theresultant lubricant of its power of absorbing oxygen. Among the adverseresults of oxidation in the crank case of a motor are the corrosiveattack on the bearings and metal of the engine and the formation of asludge compound. It is believed by those familiar with the chemi calreactions taking place during operation of internal combustion enginelubricants that oxidation is the main factor in causing break down ofthe oil and the formation of a sludge in the crank case.

I believe that the higher alcohols in the sulphurized sperm oil act as abuffer to prevent the absorption of oxygen whereas the sulphur in thesulphurized sperm oil permits the resultant mineral and sulphurizedsperm oil lubricant to take the extremely high pressures developed in aninternal combustion engine. The sulphur appears to be the catalyticmedium which enables the lubricant to establish and maintain a tenaciousoil film on the motor bearing surfaces. While the ability of sulphur tofunction as a catalytic agent to enable a lubricant to withstand a highpressure has been recognized and this property of sulphur utilized inhigh pressure lubricants for differential gear boxes and the like, noone so far as I am aware has heretofore succeeded in introducing sulphurinto a lubricant for an internal combustion engine in a form wherein thesulphur oil combination failed to corrosiveiy and adversely affect thebearings and other parts with which it came in contact.

Although I have described a lubricant and a preferred method ofproducing the same in considerable detail, I appreciate that certainmodifications and changes may be made therein by those skilled in theart without departing from the spirit of the invention as defined in thefollowing claims.

I claim:

1. A substantially non-sludging internal combustion engine lubricatingoil consisting primarily of solvent extracted de-waxed petroleum oil andnot more than about 1% of sulphurized sperm oil as an oiliness agent.

2. A substantially non-sludging internal combustion engine lubricatingoil consisting primarily of solvent extracted de-waxed petroleum oil andnot more than 1% of sulphurized liquid sperm wax as an oiliness agent.

3. An internal combustion engine lubricant 10 containing 99% of asolvent extracted de-waxed petroleum lubricating oil, and less than 1%sulphurized sperm oil acting to increase the oiliness and inhibitoxidation and sludging of the petroleum oil.

4. A substantially non-s1udging internal combustion engine lubricantconsisting primarily of a solvent extracted de-waxed petroleum oil andbetween A of 1% and 1% of sulphurized sperm oil.

FRANKQHAAS.

